Effect of water matrix on the removal of trizines pesticides by nanofiltration

The removal of two pesticides (atrazine and simazine) from different water matrix (distilled water, tap water and river water) was studied by using four types of nanofiltration membranes. Atrazine and simazine were added separately to the different water matrix at a concentration of 5 mg/l. Rejection of pesticides and water flux were measured. The rejection of atrazine was always higher than that of simazine; the highest rejections were obtained with UTC-20. Compared to distilled water, the rejection of pesticides was higher in river water and tap water, but the water flux was lower. This was mainly explained by ion adsorption inside the membrane pores or onto the membrane surface, which can narrow the membrane pores. Additionally, there was a small effect of NOM on rejection and flux. Considerable rejection of organic matter (measured as COD and UV absorbance at 254 nm) was observed, in particular for the membrane with the smallest pores (UTC-20). This confirms the assumption that pore narrowing by ion adsorption influences the rejections and water fluxes. UTC-20 was considered to be potentially a suitable one for drinking water production among the four used membranes in view of nitrate removal.